Each device contains a single unique, 96-bit, embedded, device identifier (device DNA). The identifier is nonvolatile, permanently programmed by AMD into the device via eFUSE bits, and is unchangeable, making it tamper resistant. The Device DNA is primarily used to identify the specific device.
External applications can access the DNA value through the JTAG port. FPGA designs can access the DNA internally through a Device DNA Access Port, which requires instantiation of the DNA_PORTE2 primitive. The DNA_PORTE2 primitive controls a dedicated 96-bit shift register for capturing and shifting the Device DNA value. The DNA_PORTE2 also allows for the inclusion of supplemental bits of user data, or allows for the DNA data to rollover (repeat DNA data after initial data has been shifted out).